| Cycling team | Equipo ciclista |
| Cycliophora | Cycliophora |
| cyclist | ciclista |
| cyclo- | ciclo- |
| Cyclo-cross | Ciclo-cross |
| cycloalkane | cicloalcano |
| cycloalkene | cicloalqueno |
| Cyclocomputer | Ciclocomputador |
| cyclogenesis | ciclogénesis |
| cyclohexane | ciclohexano |
| cyclohexanone | ciclohexanona |
| Cycloheximide | Cicloheximida |
| cyclone | ciclón |
| Cyclone Catarina | Ciclón Catarina |
| Cyclone Sidr | Ciclón Sidr |
| Cyclone Sidr kills hundreds in Bangladesh | El ciclón Sidr deja cientos de muertos en Bangladesh |
| cyclonic | ciclónico |
| Cyclonic separation | Ciclón |
| Cyclonite | RDX |
| Cyclop | Cíclope |
| Cyclop edia | Enciclopedia |
| Cyclopes | Cíclope |
| cyclophilin | ciclofilina |
| cyclopropene | ciclopropeno |
| cyclops | cíclope |
| Cyclorana | Cyclorana |
| cyclosilicate | ciclosilicato |
| cyclostyle | reproducir en ciclostilo |
| cyclotron | ciclotrón |
| Cyclotron radiation | Radiación ciclotrón |
| Cycnus | Cicno |
| Cydippe | Cídipe |
| Cydonia | Cara de Marte |
| Cydonia Mensae | Cara de Marte |
| cygnet | pollo de cisne |
| Cygninae | Cygnus |
| Cygnus | Cygnus |
| Cygnus columbianus | Cygnus columbianus |
| Cygnus Hyoga | Hyōga |
| Cygwin | Cygwin |
| CYK algorithm | Algoritmo CYK |
| cylinder | rodillo |
| Cylinder capacity | Cilindrada |
| cylinder head | culata |
| Cylinder of Nabonidus | Cilindro de Nabonido de Sippar |
| Cylinder seal | Sello cilíndrico |
| cylindric | cilindrico |
| cylindrical | cilíndrico |
| Cylindrical coordinate system | Coordenadas cilíndricas |
| cylindricity | cilindricidad |
| Cylindropuntia | Cylindropuntia |
| Cylon | Cylon |
| Cylon of Athens | Cilón |
| cymbal | platos |
| Cymbalaria | Cymbalaria |
| Cymbeline | Cimbelino |
| Cymbopogon | Cymbopogon |
| Cymbopogon citratus | Cymbopogon |
| Cymbopogon nardus | Cymbopogon nardus |
| Cymodoceaceae | Cymodoceaceae |
| cymotrichous | cimótrico |
| Cynan | Conan |
| Cynara | Cynara |
| Cyndi Lauper | Cyndi Lauper |
| Cynegils of Wessex | Cynegils de Wessex |
| Cynetes | Conios |
| cynic | cínico |
| cynical | cínico |
| cynically | cínicamente |
| cynicism | desengaño |
| Cynipoidea | Cynipoidea |
| Cynisca | Cinisca |
| cynism | cinismo |
| Cynodon | Cynodon |
| Cynodon dactylon | Cynodon dactylon |
| Cynoglossum | Cynoglossum |
| Cynoglossum officinale | Cynoglossum officinale |
| Cynognathus | Cynognathus |
| Cynosura | Cinosura |
| cynosure | foco |
| Cynosurus | Cynosurus |
| Cynthia | Cintia |
| Cynthia Rothrock | Cynthia Rothrock |
| Cyparissus | Cupressus |
| Cyperaceae | Cyperaceae |
| Cyperales | Cyperales |
| Cyperus | Cyperus |
| Cyperus alternifolius | Cyperus alternifolius |
| Cyperus esculentus | Cyperus esculentus |
| Cyperus papyrus | Cyperus papyrus |
| cypres | ciprés |
| cypress | ciprés |
| Cypress Hill | Cypress Hill |
| Cypria | Cipria |
| Cyprian | Cipriano de Cartago |
| Cyprien Ntaryamira | Cyprien Ntaryamira |
| Cyprinid | Cyprinidae |
| Cypriniformes | Cypriniformes |
| Cyprinodontiformes | Atheriniformes |
| Cyprinus | Cyprinidae |
| Cypriot | chipriota |
| Cypriot First Division | Primera División de Chipre |
| Cypriot Orthodox Church | Iglesia Ortodoxa Chipriota |
| Cypriot pound | Libra chipriota |
| Cypriot proverbs | Proverbios chipriotas |
| Cypripedium | Cypripedium |
| Cypripedium acaule | Cypripedium acaule |
| Cypripedium calceolus | Cypripedium calceolus |
| Cyprus | Chipre |
| Cyprus Airways | Cyprus Airways |
| Cyprus Broadcasting Corporation | Cyprus Broadcasting Corporation |
| Cyprus DLR station | Chipre |
| Cyprus Football Association | Asociación de Fútbol de Chipre |
| Cyprus in the Eurovision Song Contest | Chipre en el Festival de la Canción de Eurovisión |
| Cyprus national football team | Selección de fútbol de Chipre |
| Cyprus Stock Exchange | Bolsa de valores de Chipre |
| Cypselus | Cipselo |
| Cyrano de Bergerac | Cyrano de Bergerac |
| Cyrenaica | Cirenaica |
| Cyrenaics | Escuela cirenaica |
| Cyrene | Cirene |
| Cyrenian | cirenaico |
| Cyril | Cirilo |
| Cyril Norman Hinshelwood | Cyril Norman Hinshelwood |
| Cyril of Alexandria | Cirilo de Alejandría |
| Cyril of Jerusalem | Cirilo de Jerusalén |
| Cyril Raffaelli | Cyril Raffaelli |
| Cyril Scott | Cyril Meir Scott |
| Cyrilic script | Alfabeto cirílico |
| Cyrillic | cirílico |
| Cyrillic alphabet | cirílico |
| Cyrillic numerals | Numeración cirílica |
| Cyrillization | cirilización |
| Cyrillization of Chinese from pinyin | Cirilización del chino mandarín |
| Cyrillization of Japanese | Cirilización del japonés |
| Cyrus | Ciro |
| Cyrus cylinder | Cilindro de Ciro |
| Cyrus I of Anshan | Ciro I |
| Cyrus IMAP server | Ciro |
| Cyrus the Great | Ciro II el Grande |
| Cyrus the Younger | Ciro el Joven |
| Cyrus Vance | Cyrus Vance |
| Cyrus West Field | Cyrus West Field |
| cyst | quiste |
| cysteine | cisteína |
| cystic | cístico |
| cystic fibrosis | fibrosis quística |
